微裂纹不同接触状态下的光声非线性  

Photoacoustic Nonlinearity of Microcracks Under Different Contact States

作　　者：张逸飞 袁玲[1] 倪辰荫[2] 沈中华[1] 陆建[1] Zhang Yifei;Yuan Ling;Ni Chenyin;Shen Zhonghua;Lu Jian(School of Science,Nanjing University of Science&Technology,Nanjing,Jiangsu 210094,China;School of Electronic and Optical Engineering,Nanjing University of Science&Technology,Nanjing,Jiangsu 210094,China)

机构地区：[1]南京理工大学理学院,江苏南京210094 [2]南京理工大学电子工程与光电技术学院,江苏南京210094

出　　处：《激光与光电子学进展》2021年第7期196-203,共8页Laser & Optoelectronics Progress

基　　金：国家自然科学基金(61975080)。

摘　　要：基于光声非线性混频方法检测微裂纹时,非线性声信号特性受裂纹接触状态的影响,而裂纹的接触状态受其初始宽度、壁面形貌、调制强度等因素的影响,导致检测过程中声波与微裂纹相互作用的非线性机制发生变化。因此,建立了光声非线性混频微裂纹检测的二维物理模型,利用罚函数法实现裂纹壁间的接触约束。将本模型的实验结果与现有实验结果进行对比分析,验证了本模型的适用性;研究了不同接触状态下的声信号特性,进而分析了非线性机制受裂纹接触状态变化的影响,为研究微裂纹的光声非线性检测提供了理论参考。When detecting microcracks based on the photoacoustic nonlinear frequency-mixing method,the characteristics of nonlinear acoustic signals are affected by the crack contact state,which is affected by its initial width,wall morphology,modulation intensity,and other factors.This results in a change in the detection process of the nonlinear mechanism of the interaction between acoustic waves and microcracks.Therefore,in this paper,a two-dimensional physical model is established to analysis the nonlinear frequency-mixing process of crack detection,and the penalty method is used for the enforcement of contact constraints.The experimental result of the model are compared and analyzed with existing experimental results to verify the applicability of the model.The acoustic signal characteristics are investigated under different contact states,and the nonlinear mechanism is affected by the change of the crack contact state,which provides a theoretical reference for studying the photoacoustic nonlinear detection of microcracks.

关 键 词：测量与计量 无损检测 非线性混频 罚函数法 接触状态 非线性旁瓣 

分 类 号：TN249[电子电信—物理电子学]